* {
    margin: 0;
    padding: 0;
}

li {
    list-style: none;
}

.box {
    position: relative;
    width: 1200px;
    height: 420px;
    background: pink;
    margin: 100px auto;
}

.box img {
    width: 100%;
    height: 100%;
}

.box .prev,
.next {
    position: absolute;
    top: 50%;
    margin-top: -15px;
    width: 20px;
    height: 30px;
    color: #fff;
    /* background: rgba(0, 0, 0, .7); */
    background: red;
    text-align: center;
    line-height: 30px;
    text-decoration: none;
}

.box .prev {
    left: 0;
    border-radius: 0 10px 10px 0;
}

.box .next {
    right: 0;
    border-radius: 10px 0 0 10px;
}

.box .promo-nav {
    position: absolute;
    bottom: 15px;
    left: 50%;
    margin-left: -35px;
    width: 70px;
    height: 13px;
    background: rgba(255, 255, 255, .3);
    border-radius: 7px;
}

.box .promo-nav li {
    float: left;
    width: 8px;
    height: 8px;
    border-radius: 50%;
    background: #fff;
    margin: 3px;
}

.box .promo-nav .active {
    background: orange
}